Reconfigurable Carbon Nanotube Multiplexed Sensing Devices

Abstract

Here we report on the fabrication of reconfigurable and solution processable nanoscale biosensors with multisensing capability, based on single-walled carbon nanotubes (SWCNTs). Distinct DNA-wrapped (hence water-soluble) CNTs were immobilized from solution onto different prepatterned electrodes on the same chip, via a low-cost dielectrophoresis (DEP) methodology. The CNTs were functionalized with specific, and different, aptamer sequences that were employed as selective recognition elements for biomarkers indicative of stress and neuro-trauma conditions. Multiplexed detection of three different biomarkers was successfully performed, and real-time detection was achieved in serum down to physiologically relevant concentrations of 50 nM, 10 nM, and 500 pM for cortisol, dehydroepiandrosterone-sulfate (DHEAS), and neuropeptide Y (NPY), respectively. Additionally, the fabricated nanoscale devices were shown to be reconfigurable and reusable via a simple cleaning procedure. The general applicability of the strategy presented, and the facile device fabrication from aqueous solution, hold great potential for the development of the next generation of low power consumption portable diagnostic assays for the simultaneous monitoring of different health parameters.

Immunobinding‐induced alteration in the electrophoretic mobility of proteins: An approach to studying the preconcentration of an acidic protein under cationic isotachophoresis

“…Thus, with the the power of online preseparation and concentration, our cationic paper‐based ITP provides more favorable conditions for target capture and detection. Also, some nano‐technologies based assays, such as carbon nanotube and nanowire technologies , can achieve high sensitivity and specificity, but complex fabrication and requirement of expensive equipment make them less suitable for POC application.…”

Immobilization of Target-Bound Aptamer on Field Effect Transistor Biosensor to Improve Sensitivity for Detection of Uncharged Cortisol

“…The condition of 0 μmol L -1 cortisol means that the aptamer molecules were directly immobilized on the FET gate surface without reacting with cortisol. After immobilization, the FET chips were immersed in 8 mol L -1 urea aqueous solution 16 for 60 min to remove cortisol molecules from the cortisol-bound aptamer. Finally, the unreacted aldehyde groups of GA were treated with 10 mmol L -1 tris(hydroxymethyl)aminomethane (Tris; Tokyo Chemical Industry Co., Ltd., Tokyo Japan).…”

Direct Synthesis of Multiplexed Metal‐Nanowire‐Based Devices by Using Carbon Nanotubes as Vector Templates

“…Cu(acac) 2 @SWNT, Pt(acac) 2 @SWNT, and [Pt(acac) 2 +Cu(acac) 2 ]@SWNT were dispersed in separate SDS–water solutions, and each solution was drop cast on a silicon wafer with prepatterned electrode pairs (see the Supporting Information for details). The SWNT hybrids were immobilized between the electrode pairs by DEP, in a field effect transistor (FET) configuration (Figure ). By repeating this process with different solutions of distinct SWNT hybrids while addressing, through DEP, different electrode‐pair locations on the same substrate surface, it is possible to immobilize distinct metal acetylacetonate (M(acac) 2 , M=Cu and/or Pt) SWNT hybrids (M(acac) 2 @SWNTs) at separate locations on the same chip (Figure ; see also the Supporting Information) .…”

“…The SWNT hybrids were immobilized between the electrode pairs by DEP, in a field effect transistor (FET) configuration (Figure ). By repeating this process with different solutions of distinct SWNT hybrids while addressing, through DEP, different electrode‐pair locations on the same substrate surface, it is possible to immobilize distinct metal acetylacetonate (M(acac) 2 , M=Cu and/or Pt) SWNT hybrids (M(acac) 2 @SWNTs) at separate locations on the same chip (Figure ; see also the Supporting Information) . Finally, the sample was washed with water to remove the SDS and purged with nitrogen gas.…”